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Finding the Fourth Proportional to 891.40, 1,230.13 and 518.39

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Solution

The fourth proportional to 891.40, 1,230.13 and 518.39 is: 715.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    891.40 : 1,230.13 = 518.39 : x
  2. Step 2: Convert to fraction form
    891.40/1,230.13 = 518.39/x
  3. Step 3: Cross multiply
    891.40x = 1,230.13 × 518.39
  4. Step 4: Simplify right side
    891.40x = 637,682.24
  5. Step 5: Solve for x
    x = 637,682.24/891.40
  6. Step 6: Final answer
    x = 715.38

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Double scale
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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.